Term
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Definition
| a substance with hygroscopic properties |
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Term
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Definition
α1-‐6 glucosidic linkage every 24-‐30
units
vs
a1--6 occurs every 8-‐12 units |
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Term
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Definition
| breakdown of starch molecules to smaller, sweeter, tasting dextrin molecules in the presence of dry heat |
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Term
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Definition
| increase in volume, viscosity, and translucency of starch granules as they swell disrupting their granular structure |
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Term
| Gelation definition, and how its affect by acid and sugar |
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Definition
formation of a gel upon cooling; agitation during cooling disrupts amylose network that would form
acid & sugar both decrease gelation |
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Term
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Definition
| reversion back to crystalline structure upon cooling of starch after heating |
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Term
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Definition
| weeping of gel due to excessive retrogradation of starch |
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Term
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Definition
| changes in gelatinized starch beyond gelation temperature, including considerable loss of amylose, loss of viscosity and implosion of starch granule |
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Term
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Definition
| Starch with nearly all branched amylopectin chains |
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Term
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Definition
| starch that has been chemically or physically modified to create unique functional properties |
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Term
| What is the amylose to amylopectin conent of Hi amylose? |
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Definition
| 75% amylose, 25% amylopectin |
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Term
| What distinguishes RS 1 through 4? |
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Definition
RS1: Trapped in cells (seeds/legumes)
RS2: Native starch (raw potatoes, bananas)
RS3: Cyrstalline, non-granular starch( cooked & cooled potatoes)
RS4: Chemically or genetically modified |
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Term
| What are the 4 general qualities of reistant starches? |
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Definition
Small intestine is unable to digest, limited digestion in large intestine; fermentation in colon
Take up less water than other fibers, making dough less sticky
Smooth even texture
Less than 3 cal/g |
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Term
| What are the 5 features of oxidized starch? |
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Definition
Exposed to chemical oxidizers (Na hypochlorite)
Less viscous, clear vs. opaque
Used as emulsion stabilizer and thickener
Food applications include dusting foods such as marshmallows & chewing gum |
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Term
| What are the 3 features of cross linked starch and what foods is it typically found in? |
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Definition
Chemically treated starch that has been modified to link starch molecules with cross-bridges
Less likely to lose viscosity with heat
Prevents solidification
used for cooked or canned foods, pie fillings, bakery glazes, frozen pizza dough, puddings |
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Term
| What are the 7 functions of starch? |
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Definition
Flavor
Edible Film
Stabilizers
Water or Fat binders
Fat substitutes
Emulsification aids
Thickeners |
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Term
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Definition
| Turning amorphous glass substances into amorphous rubbery substances |
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Term
| What are starch granules good for? |
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Definition
| They make excellent emulsifiers due to lipid and amylose complexes |
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Term
| What are the three thickened sauce examples given? |
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Definition
| cheese, custard (egg), white sauce & variations of white sauce (milk) |
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Term
| Starch heated dry vs in water |
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Definition
Dextrinization (dry heat)
vs
Gelatinization (in water) |
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Term
| Describe the process of gelatinization (5) |
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Definition
Thermal energy causes hydrogen bonds to break allowing water to enter the starch granule
swelling of starch as H bonding of water with amylopectin molecules within the starch granule
amylose molecules released into the water
the larger size of the amylose molecules, the greater the tendency to create a stronger gel
Reduced free water changes the viscosity of the starch mixture, thickening it |
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Term
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Definition
| Solid in a liquid; Initial stage of gelatinization as starch in solution |
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Term
| What is required for the formation of a gel from starch? |
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Definition
| Sufficient amylose present in initial type of starch used |
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Term
| Which starch would be best for making something like a pie crust? |
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Definition
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Term
| What are the 7 factors that affect gelatinization? |
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Definition
Temperature
Type of starch
Mechanical Energy (stirring)
Sugar
Acid (pH preferred > 4)
Fat/Protein content
Cross linked starches |
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Term
| How does sugar affect gelatinization? (2) |
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Definition
It is also hygroscopic and competes with starch for water absorption
Decreases temperature |
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